1. Field
This disclosure generally relates to evaluation systems, and more particularly to systems that evaluate characteristics of substances using electromagnetic energy.
2. Description of the Related Art
Various systems employ spectral analysis returned from a sample of a substance to analyze the sample and/or recognize the substance.
For example, U.S. Pat. No. 8,076,630 describes systems and methods of evaluating objects using electromagnetic energy. In particular, U.S. Pat. No. 8,076,630 teaches a system for evaluating subject objects, the system which includes at least one physical source operable to emit electromagnetic energy and driver electronics drivingly coupled to at least one physical source. The driver electronics drive at least one physical source as a number of logical sources, using an electromagnetic forcing function where the number of logical sources is greater than the number of physical sources. In addition, the system includes a sensor to receive an electromagnetic response from at least a portion of an evaluation object illuminated by one or more physical sources operated as logical sources, and convert the electromagnetic response to a test response signal indicative of the electromagnetic response of the evaluation object.
Also for example, U.S. Pat. No. 7,996,173 describes methods, apparatus and articles to facilitate distributed evaluation of objects using electromagnetic energy. In particular, U.S. Pat. No. 7,996,173 teaches that objects such as manufactured goods or articles, works of art, media such as identification documents, legal documents, financial instruments, transaction cards, other documents, and/or biological tissue are sampled via sequential illumination in various bands of the electromagnetic spectrum, and a test response to the illumination is analyzed with respect to reference responses of reference objects. U.S. Pat. No. 7,996,173 teaches that the sequence may be varied. For instance, the sequence may define an activation order, a drive level and/or temperature for operating one or more sources. Illumination may be in visible, infrared, ultraviolet, or other portions of the electromagnetic spectrum. U.S. Pat. No. 7,996,173 further teaches that elements of the evaluation system may be remote from one another, for example communicatively coupled via a network.
As a further example, U.S. Pat. No. 8,081,304 describes the use of spectral information in process control and/or quality control of goods and articles. In particular, U.S. Pat. No. 8,081,304 describes the use of spectral information in process control and/or quality control of media, for example financial instruments, identity documents, legal documents, medical documents, financial transaction cards, and/or other media, fluids for example lubricants, fuels, coolants, or other materials that flow, and in machinery, for example vehicles, motors, generators, compressors, presses, drills and/or supply systems. U.S. Pat. No. 8,081,304 further describes the use of spectral information in identifying biological tissue and/or facilitating diagnosis based on biological tissue.
The above described patents are only representative.